Make ChangeCipherSpec compliant with DTLS RFC4347. From HEAD with a twist:

server interoperates with non-compliant pre-0.9.8f.

diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index 7e6d300377ac383c116c5e064e9ab65a08f84ff8..a17ebfa925c4392c7dc4a2c9980cd373323b9b09 100644 (file)
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -816,9 +816,14 @@ int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
                *p++=SSL3_MT_CCS;
                s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
                s->d1->next_handshake_write_seq++;
-               s2n(s->d1->handshake_write_seq,p);
-
                s->init_num=DTLS1_CCS_HEADER_LENGTH;
+
+               if (s->client_version == DTLS1_BAD_VER)
+                       {
+                       s2n(s->d1->handshake_write_seq,p);
+                       s->init_num+=2;
+                       }
+
                s->init_off=0;
 
                dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 
@@ -1056,7 +1061,7 @@ dtls1_buffer_message(SSL *s, int is_ccs)
     if ( is_ccs)
         {
         OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
-            DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
+            DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
         }
     else
         {
@@ -1259,5 +1264,4 @@ dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
     memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
     
     ccs_hdr->type = *(data++);
-    n2s(data, ccs_hdr->seq);
 }

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index 24ef9ec3d2b27645303e36cdf6c8eefd0df0e806..333a26c0c2845f981f94888070340721bd42a14f 100644 (file)
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -974,47 +974,40 @@ start:
                }
 
        if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
-        {
-        struct ccs_header_st ccs_hdr;
+               {
+               struct ccs_header_st ccs_hdr;
 
                dtls1_get_ccs_header(rr->data, &ccs_hdr);
 
-               if ( ccs_hdr.seq == s->d1->handshake_read_seq)
-                       {
-                       /* 'Change Cipher Spec' is just a single byte, so we know
-                        * exactly what the record payload has to look like */
-                       /* XDTLS: check that epoch is consistent */
-                       if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) || 
-                               (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
-                               {
-                               i=SSL_AD_ILLEGAL_PARAMETER;
-                               SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
-                               goto err;
-                               }
-                       
-                       rr->length=0;
-                       
-                       if (s->msg_callback)
-                               s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
-                                       rr->data, 1, s, s->msg_callback_arg);
-                       
-                       s->s3->change_cipher_spec=1;
-                       if (!ssl3_do_change_cipher_spec(s))
-                               goto err;
-                       
-                       /* do this whenever CCS is processed */
-                       dtls1_reset_seq_numbers(s, SSL3_CC_READ);
-                       
-                       /* handshake read seq is reset upon handshake completion */
-                       s->d1->handshake_read_seq++;
-                       
-                       goto start;
-                       }
-               else
+               /* 'Change Cipher Spec' is just a single byte, so we know
+                * exactly what the record payload has to look like */
+               /* XDTLS: check that epoch is consistent */
+               if (    (s->client_version == DTLS1_BAD_VER && rr->length != 3) ||
+                       (s->client_version != DTLS1_BAD_VER && rr->length != DTLS1_CCS_HEADER_LENGTH) || 
+                       (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
                        {
-                       rr->length = 0;
-                       goto start;
+                       i=SSL_AD_ILLEGAL_PARAMETER;
+                       SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
+                       goto err;
                        }
+
+               rr->length=0;
+
+               if (s->msg_callback)
+                       s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
+                               rr->data, 1, s, s->msg_callback_arg);
+
+               s->s3->change_cipher_spec=1;
+               if (!ssl3_do_change_cipher_spec(s))
+                       goto err;
+
+               /* do this whenever CCS is processed */
+               dtls1_reset_seq_numbers(s, SSL3_CC_READ);
+
+               /* handshake read seq is reset upon handshake completion */
+               s->d1->handshake_read_seq++;
+
+               goto start;
                }
 
        /* Unexpected handshake message (Client Hello, or protocol violation) */